The area of renewable energy has in recent years, due to the threat of global warming and other related issues, seen significant advances, with large resources and investment being channelled into developing new or improved forms of renewal energy. One particular area which holds significant potential is in the harnessing of tidal energy, in particular through the use of seabed deployed hydroelectric turbines. These turbines can run essentially twenty four hours a day delivering consistent energy and without any environmental impact or other drawbacks.
However, harnessing tidal energy does provide its own challenges, in particular with respect to the installation and maintenance of tidal power generators, for example hydro-electric turbines, which by the very nature of the operation of same must be located in relatively fast flowing tidal currents, and more than likely located on the seabed. In addition, in order to be economically viable these turbines must be built on a large scale. As a result the turbines and associated bases/supports are large and cumbersome components, and require significant heavy lifting and transport equipment in order to achieve deployment and retrieval for maintenance purposes. The use of such heavy lifting equipment is normally a hazardous undertaking, and is rendered even more dangerous when this equipment is operated at sea under difficult and unsteady conditions. As a result the retrieval process may take some time to complete. Furthermore, as the turbines are located on the seabed it is not generally possible or at least economically feasible to implement continuous visual monitoring of the turbines to check for damage to the turbine. It is therefore highly desirable that these hydroelectric turbines are relatively simple machines, and therefore reliable, and that the working components of same have a significant operating life.
One of the components most likely to suffer damage is the coils used in the electromagnetic circuit, which can, for a number of reasons, overheat and malfunction, leading to possible damage to both the electromagnetic circuit and potentially other areas of the turbine. This will at the least result in a reduction of the power output of the turbine, and may result in the total shutdown or inoperability of the turbine, therefore requiring retrieval and repair of the turbine.
It is thus an object of the present invention to overcome the above mentioned problems.